Maybe I shouldn't have started this blog now, not with everything that's been going on.

Returning to my first lecture in Electromagnetic Theory for the sixth week of classes, from electric fields we proceeded to electric flux, which is solved by using a closed integral along a surface and the dot product of the vector associated with the area (always pointed outwards) and the electric field.

I reminded them that back in electricity and magnetism lecture we merely had cubes for our examples on this, but now it can be any type of surface, such as a cylinder.

And even when we returned to examples using a cube, it was a bit more complicated with the unit vectors in the same directions as the axes (i-hat, j-hat and k-hat) and the electric field given by an equation in three variables.

In Advanced Mathematics’ first class for the sixth week, I taught them another method of getting the solutions of linear equations, using the product of the constants from the equations and the inverse of the matrix of the coefficients.

At least this time we used the solution of the same equations we had before, so there was no more need for verification.

Afterwards we also took up eigenvectors and their values, for a scalar that is the equated to a matrix multiplied to the same vector of unknowns.

Since there were eight students I have devised several ways of dividing them into different groups, from alphabetical to by height to the lengths of their names, just so that exercises are not individual anymore, because who are we fooling? They are consulting with each other anyway.

In mechanics classes I made two exams again. The first one had eleven items (and thus could be afforded ten points each) while the second I neglected to count beforehand had twelve items (and were then relegated to nine points each).

As I had promised them, stating Newton’s Laws of Motion was already one (three?) of the items.

And typical of the case for rushing the questions the hour before the exams are due, there were typographical errors, one in the first and three in the second. The initial velocity was missing, the faster and slower cars were reversed in an overtaking situation, an exponent wasn’t there and the mass of Lois Lane inside a safe was not directly stated.

There were an equal number of easy and difficult questions per set.
In the first there was whether a car would hit a hotdog stand, where the distance between the two was intended to confuse for the displacement (which it was not). For a badminton shuttlecock that hit the ceiling, its velocity becomes zero at the start of its downward journey. Lastly, the additional mass a boy loads on a carriage that he and girl push for forces.

I’ll talk about the second set of questions tomorrow, and the continuation of the sixth week of classes. We’re done for today.